In recent years, with evolution of the electronic industry and rapid development of the industrial technology, various electronic devices are designed and developed toward a direction of being portable and easy for carrying, so as to be applied by a user for commercial affairs, entertainments, or leisure at anytime and anywhere. For example, various image capture devices are widely applied to various fields. For example, an electronic device such as a smartphone, a wearable electronic device, or an aerial photographic device has advantages of being small in volume and convenient for carrying. Therefore, the user is enabled to take out the electronic device anytime when the user needs to use and capture and save an image, or further to upload the image to the Internet by using the network; this does not merely have an important commercial value but further makes people's daily life colorful. However, with improvement of the quality of life, people have more demands on images, and especially hope that an obtained image has higher imaging quality or more imaging effects.
For example, to highlight a target in the image, people hope that areas other than the target in the image are fuzzier than the target, that is, a background blurring function. In detail, referring to FIG. 1, FIG. 1 is a conceptual schematic diagram of an optical path of an existing image capture device provided with a background blurring function. An image capture device 1 includes an optical lens 11 and an image sensing element 12. The optical lens 11 is located between a target A1 of a shot scene and an imaging surface 121 of the image sensing element 12. Moreover, an optic axis 19 of the optical lens 11 is vertical to the imaging surface 121 of the image sensing element 12. In a process that the image capture device 1 shoots an image, the image capture device 1 may perform focusing after the target A1 is selected, so that a light beam group L11 from the target A1 may be focused to the imaging surface 121 of the image sensing element 12 after passing through the optical lens 11. Further, the image capture device 1 may obtain a clear image of the target A1. However, a light beam group L12 from another target (for example, another target B1 at a position different from that of the target) would not be focused to the imaging surface 121 of the image sensing element 12 after passing through the optical lens 11. Therefore, in the image obtained by the image capture device 1, other image areas other than the target A1 are relatively fuzzy, so as to present a background blurring effect.
However, the prior art can merely provide a single-point focusing background blurring function. That is, an image shot by the image capture device cannot have the effect of enabling a plurality of targets clear but other image areas fuzzy. Therefore, requirements of the user who hopes to highlight a plurality of selected targets in the image cannot be satisfied. Therefore, the conventional image focusing method may be improved.